<form method="post" action="{:U('insert','','')}">
    标题:<input type="text" name="title"><br/>
    内容：<textarea name="content" rows="5" cols="45"></textarea><br/>
<input type="text" value="vcode">
<img src="{:U('vcode','','')}" onclick="this.src=this.src+'?'+Math.random()"/><br/>
<input type='submit' value="提交">
</form>